glfw/tests/tearing.c

108 строки
3.0 KiB
C

//========================================================================
// Vsync enabling test
// Copyright (c) Camilla Berglund <elmindreda@elmindreda.org>
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
// claim that you wrote the original software. If you use this software
// in a product, an acknowledgment in the product documentation would
// be appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such, and must not
// be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source
// distribution.
//
//========================================================================
//
// This test renders a high contrast, horizontally moving bar, allowing for
// visual verification of whether the set swap interval is indeed obeyed
//
//========================================================================
#include <GL/glfw3.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
static int swap_interval;
static void set_swap_interval(GLFWwindow window, int interval)
{
char title[256];
swap_interval = interval;
glfwSwapInterval(swap_interval);
snprintf(title, sizeof(title),
"Tearing detector (interval %i)",
swap_interval);
glfwSetWindowTitle(window, title);
}
static void window_size_callback(GLFWwindow window, int width, int height)
{
glViewport(0, 0, width, height);
}
static void key_callback(GLFWwindow window, int key, int action)
{
if (key == GLFW_KEY_SPACE && action == GLFW_PRESS)
set_swap_interval(window, 1 - swap_interval);
}
int main(void)
{
float position;
GLFWwindow window;
if (!glfwInit())
{
fprintf(stderr, "Failed to initialize GLFW: %s\n", glfwErrorString(glfwGetError()));
exit(EXIT_FAILURE);
}
window = glfwOpenWindow(0, 0, GLFW_WINDOWED, "", NULL);
if (!window)
{
glfwTerminate();
fprintf(stderr, "Failed to open GLFW window: %s\n", glfwErrorString(glfwGetError()));
exit(EXIT_FAILURE);
}
set_swap_interval(window, swap_interval);
glfwSetWindowSizeCallback(window_size_callback);
glfwSetKeyCallback(key_callback);
glMatrixMode(GL_PROJECTION);
glOrtho(-1.f, 1.f, -1.f, 1.f, 1.f, -1.f);
glMatrixMode(GL_MODELVIEW);
while (glfwGetCurrentContext())
{
glClear(GL_COLOR_BUFFER_BIT);
position = cosf(glfwGetTime() * 4.f) * 0.75f;
glRectf(position - 0.25f, -1.f, position + 0.25f, 1.f);
glfwSwapBuffers();
glfwPollEvents();
}
glfwTerminate();
exit(EXIT_SUCCESS);
}